干旱胁迫对鸢尾苗生理指标的影响

采用聚乙二醇(PEG-6000)浓度为0、10%、20%、30%4种溶液,进行模拟干旱试验,对长白山地区的溪荪、玉蝉花、山鸢尾3种鸢尾苗进行渗透胁迫,测定其膜相对透性(RP)、脯氨酸(Pro)含量、过氧化物酶(POD)活性的变化,研究在水分胁迫条件下3种鸢尾苗细胞膜透性,渗透调节物质以及保护酶系统的变化情况及对植物的伤害过程和对逆境的反应。结果表明:渗透胁迫36、72h之后,叶片的质膜相对透性均有不同程度的升高,其中以山鸢尾的上升幅度最大,溪荪上升幅度最小;脯氨酸(Pro)含量随着干旱胁迫浓度的增加,均有不同程度上升,溪荪上升的幅度较小;过氧化物酶(POD)也均有上升,溪荪和玉蝉花上升幅度较大,而山鸢尾上升趋于平缓。研究表明,较小的质膜透性和脯氨酸含量,及较大POD活性,可以作为鸢尾抗旱的3个重要指标。综合分析认为,3种鸢尾植物的抗旱性由强至弱的顺序为溪荪玉蝉花山鸢尾。

Effect of Drought Stress on Physiological Indexes in Seedlings of Iris

The drought method was taken by the Polyethylene glycol(PEG-6000) with four kinds of solution concentration: 0,10%,20% and 30%.Under the osmotic stress,Iris ensata,Iris setosa and Iris sanguinea in the Changbai Mountain area were researched,their relative membrane permeability(RP),proline(Pro) content and the changes of peroxidase(POD) activity were determined.The changes of the cell membrane permeability,osmoregulation substance and protective enzyme system of the three kinds of Iris seedlings and its injury process and stress responses to the plants under the water stress conditions were researched.The results showed that the sequence of drought resistance in three kinds of Iris plants from strong to weak was Iris sanguinea,Iris ensata,Iris setosa.After 36 h and 72 h under the osmotic stress,the relative membrane permeability of the leaves increased in varying degrees,with Iris setosa largest increase,the smallest increase in Iris sanguinea;proline(Pro) content increased with the increasing in the concentration of drought stress,the rate of increase in Iris sanguinea was smaller,the POD incresaed too.The rising amplitude of Iris sanguinea and Iris ensata were larger,and Iris setosa changed to gentle.Smaller membrane permeability and proline content with more POD activity could be three important indexes to the drought resistance of the Iris.